(1) Field of the Invention
The field of art to which the invention pertains includes the field of telescopic leg locking systems.
(2) Description of the Prior Art
Conventional locking systems for telescoping members utilize either a positive type locking system or a continuously adjustable locking system. In the positive type system, the telescoping members can be adjusted at periodically spaced points along the axes of both legs. A typical arrangement utilizes a pin which passes through apertures in both of the telescoping members. The disadvantage in such an arrangement is that the telescoping members can only be adjustable in length at fixed periodic intervals.
Continuously adjustable systems typically utilize an offset cam member. Rotation of the cam member causes the telescoping legs to lock in a predetermined position. Such devices, however, have been found to tend to freeze or lock after prolonged or continued use.
Known prior art includes U.S. Pat. Nos. 2,871,044; 3,419,293; 2,546,157; 3,724,885; 2,873,129; 648,461; 2,517,700; 2,850,308; 2,910,315; 64,292; 272,315; 458,580; 760,598; 1,915,669; and 3,920,342.
The present invention provides a novel, yet relatively simple locking system for a pair of continuously adjustable telescoping legs. The generally symmetrical arrangement of the system prevents locking or freezing.